Digital signatures are well known as a computer implemented technique for authenticating a message. Verification of the signature confirms that the message signed corresponds to the message received. Many digital signature schemes have been proposed and among those known signature schemes are a class of signatures that permit partial or complete recovery of the message from the signature. A particular efficient digital signature scheme is that known as the Pintsov-Vanstone signatures, commonly referred to as PV signatures.
The Elliptic Curve Pintsov-Vanstone Signature (ECPVS) scheme provides digital signatures with partial message recovery. Such schemes are presented in ANSI Draft X9.92-2007-02-21 (Public Key Cryptography for the Financial Services Industry, Digital Signature Algorithms Giving Partial Message Recovery Part 1: Elliptic Curve Pintsov-Vanstone Signatures (ECPVS), Accredited Standards Committee X9, Inc., 2007), and ISO/IEC 9796-3 (ISO/IEC 9796-3:2006: Information technology—Security techniques—Digital signature schemes giving message recovery—Part 3: Discrete logarithm based mechanisms, 2006), both of which are incorporated herein by reference,
Partial message recovery in a digital signature scheme reduces the bandwidth requirement of transmitting a (message, signature) pair. This works by “merging” a portion of the message (the recoverable portion) with the signature value (while not increasing the size of the signature), and not transmitting this part of the message. If the signature is valid, the verifier recovers the recoverable part of the message.